The invention relates to packaging and shipping systems and in particular to packaging of materials and items to be secured as a unit load or to be secured to a shipping and transporting means, such as a pallet. Specifically, it relates to such systems using plastics stretch film (a high cling film) as the binding and securing agent, and more specifically to an apparatus for such systems that is manually operable with one hand, leaving the other hand free to stabilize the load being secured.
A need has existed for some time for simple means for applying plastics stretch film material. U.S. Pat. Nos. 4,179,081 and 4,248,392, both entitled "Apparatus for Application of Plastics Stretch Films", invented by the present applicant, solved some of the problems and provided a simple and economical means to do the work. However, problems still remain when binding and securing light weight materials and items as a unit load or to a shipping and transporting means, such as a pallet or slip sheet. The present invention solves those problems.
The present invention is for manual operation, but may also be applied to machine applications of the plastics stretch film. The present invention is a one-hand operated dispensing unit which frees the other hand for steadying or stabilizing light weight materials or items, particularly when stacked. The light-weight items may be stacked for binding as a unit load or stacked on a shipping or transporting means as aforementioned. The one-hand device is especially useful when starting the binding wrapping of the plastics stretch film, and when binding the top layers in a stack. In both cases the free hand can be used to hold steady the materials or items and prevent them from sliding out of position as the film is applied for the initial layer or layers of wrapping when the light weight materials or items are not stable at their interface with each other.
The present one-hand device has a simple means included so that it can be converted to a two-hand operation once the materials or items are initially bound or secured sufficiently for a tighter wrapping for movement or for shipment. The simple means for converting to a two-hand device also serves as an efficient means for packaging a pair of the one-hand devices or a package of pairs of the one-hand devices.
In the prior art two methods were available for applying the plastics stretch film material to materials and units to be packaged or secured as hereinbefore described. In addition, now in the prior art, are the two-hand devices of the cited United States Patents, invented by the present applicant.
As described in the two cited U.S. patents, one of the prior art methods is to use a very expensive automatic machine, and the other is to use a commercial manually operated grabbing or holding device which also is very expensive and complicated. The inventions of the two cited United States Patents overcome the problems of the prior art by providing a simple manually operated means for applying the film using two hands, but was unwieldy and unuseable when binding or securing light weight materials or items as hereinbefore described. The present invention overcomes the problems.
The present invention, when used in the manner of the conversion to a two-hand device, also provides another advantage. The conversion means permits the addition of a second one-hand device so that a "roping" effect can be accomplished with a double wrap of narrow strips of plastics film for a tighter and more secure binding of a unit package or load. The details of this "roping" operation is explained hereinafter.
In the prior art the two hand device was unwieldy, as aforementioned, when binding and securing light weight materials and items, particularly when piled or stacked. The cantilever action of the two-hand device was painful and caused a severe bending moment on the wrist when held in one hand. With the extreme cantilever action it was found to be impossible with one hand to make the initial binding wrap on light-weight materials or items.
The very low cantilever action of the one-hand device of the present invention permits the initial binding of light-weight materials and items without the overpowering stress in the wrist of the user. At the same time, the other hand is available to steady or stabilize the pile or stack of materials or items. The completion of the binding and securing of the unit or load can then be accomplished by the continued use of the one-hand device of this invention, or a second one-hand device can be added by the novel and unique coupling means so that it can be operated like a two-hand device. The novel and unique coupling means also provides a simple way of shipping a pair of one-hand units, or packages of a plurality of pairs of one-hand units, as well as being the means by which a pair of one-hand devices can be used like a two-hand device.
The novel and unique coupling means makes it possible to apply the plastics film material in a roping manner of two narrow flat sheets of the plastics film. The roping method adds a criss-cross or "X" pattern that increases the strength and holding power of the plastics film binding wrap.
The roping effect is achieved when two one-hand operated devices are coupled together and periodically or intermittently, while stretching and wrapping the film around materials or items, the hand grip ends are changed to the opposite hands so as to criss-cross lap the flat plastics sheets in the wrapping procedure.
The control of the amount of tension applied to the plastics film to stretch it and to provide a tight gripping force upon the materials or items being bound into a unit or load is by the direct pressure or squeeze of the operator's one hand on the grip end of the one-hand device. The grip or squeeze by the operator is applied on a flexible tube-like device, the flexible tube-like device or grip means being applied around an extended end of the core means of a one-hand roll of the plastics film material.
The coupling means for using two one-hand devices simultaneously and for shipping the devices in pairs is a dowel-like member that is dimensionally longer than the core length of a single one-hand device, but dimensionally shorter than two core lengths of a one-hand device. To couple two one-hand devices to each other for operating as a two-hand device or for shipping a pair of units, the dowel-like member is slideably inserted into the two hollow cylindrical cores of each of the two one-hand units. The diameter of the dowel-like member is dimensionally less than the inside diameter of the core. The grip means on each extended core end of the two one-hand devices are then held and the combination used like a two-hand device.
When using the one-hand device in one hand, the dowel-like member can be left out or placed in the one-hand device in use. If, momentarily, the one-hand device needs a temporary support, the free hand can grip the dowel-like member where it protrudes from the core of the one-hand device in use. The dowel-like member, being dimensionally smaller in diameter than the inside diameter of the core, will move freely in the core. The dowel-like member can, in this case, be gripped tightly by the free hand as only temporary support is necessary.
Two types of hand grips are disclosed in the present invention as components of the invention. One is a tubular-like member with a closed end. The other is an improved hand grip that is also tubular-like, but is improved with a flange means on one end and an inward turned lip on the other end instead of a closed end.
It is, therefore, an object of this invention to provide a plastics film dispensing means that is operable with one hand.
It is another object of this invention to provide a one-hand operated plastics film dispensing means that has a low cantilever action on the wrist of the user.
It is also an object of this invention to provide a one-hand operated plastics film dispensing means in which the operator can "feel" the movement and tension condition through the hand on the flexible hand grip of the device, while the free hand is available to steady and stabilize light weight materials and items being bound and secured as a unit or for shipment.
It is yet another object of this invention to provide a one-hand operated plastics film dispensing means that has a simple coupling means for removably and revolvably affixing a second one-hand operated plastics film dispensing means to the first plastics film dispensing means so that the two one-hand operated plastics film dispensing means may be operated as a two-hand plastics film dispensing means.
It is still another object of this invention to provide a one-hand operated plastics film dispensing means that can apply two plastics films in a roping manner when coupled with a second one-hand operated plastics film dispensing means.
Further objects and advantages of the invention will become apparent in the light of the following description of the preferred embodiments.